Directly measuring combustion pressure inside cylinders Helps optimize combustion in engines

TOP > Combustion Pressure Sensor

Combustion pressure sensors that concentrate the technology of the Citizen Group

The combustion sensors concentrate the Citizen Group’s piezoelectric crystal, ceramic and metalworking technology along with the technology to mass produce compact precision components.
In addition to the conventional development applications, they can be installed in the internal combustion engines of mass production vehicles to improve compliance with environmental regulations and fuel economy.


Sensors Employing Langasite-type Crystals

Sensors Employing Langasite-type

Integrated Production from Element Development to Assembly

Integrated Production from
Element Development to Assembly


In-house development of “langasite-type crystal” piezoelectric elements

Langasite-type crystals, which are able to demonstrate their piezoelectric element performance even in high-temperature environments, are adopted. Drawing on our experience as a crystal manufacturer, we handle everything from growing crystals to processing them in-house.


Integrated production using equipment and technologies built up in the Citizen Group

We apply the technology for mass production of small precision parts, in which we can boast accuracy in micron units, built up in watch manufacture. Along with that we have established in-house manufacture/integrated production of key components including elements.

High pressure-resistant, High-performance Sensors

High pressure-resistant,
High-performance Sensors

Installable in High performance Vehicles

Installable in
High performance Vehicles

In-house test bench knocking waveform

Measurement of knocking also possible

High pressure-resistant and high-performance sensors are realized by adopting crystals with high heat resistance and applying watch manufacturing technology. They are of course used for measuring knocking, and also for applications including ignition timing control.


Installation in mass production vehicles achieved!!

Using our unique sensor structure ensures high durability. Their installation in mass production vehicles has been achieved by establishing mass production technology for them.Measuring the pressure inside constantly changing cylinders helps realize the optimum combustion conditions.

Installable in High performance Vehicles

Installable in High performance Vehicles


Installable in High performance Vehicles

Due to their high durability and performance, these sensors can be used in development (test bench) situations such as for High power engine and supercharged engines, and for installation in actual vehicles. They maximize engine performance.




Supercharging Vehicles

Supercharging Vehicles


For automotive

Type CAS-30
Measuring range(MPa) 0~25
Sensitivity (pC/MPa)
Linearity(%FSO) ≦±1.0
Natural frequency(KHz) >140
Insulation resistance(?) ≧1013
Operating range(℃) ~350℃
Cable connection(mm) M8×1
Cooling Non-cooling
Cable Low noise cable for exclusive use
  • ※Accuracy is different depending on the installation method.
    ※Please inquire the method of connecting the sensor and the connector.
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For Supercharging engine、High power Engine

Type MCX02 MCX03
Use application High output and supercharged engine etc.
Measuring range(MPa) 0∼80MPa(0~800bar) 0∼40MPa(0~400bar)
Sensitivity (pC/MPa) -13pC/bar -15pC/bar
Linearity(%FSO)) ≦±0.5%FSO
Natural frequency(KHz) >110KHz >120KHz
Insulation resistance(?) ≧10¹³
Operating range(℃) -40∼400(℃)
Thermal shock error ≦±1.0bar ≦±0.5bar
Mounting dimensions(mm) Standard size:M5×0.5、HEX:4(mm)
Cooling Non-cooling
Mounting torque 1.5Nm



Basic specifications sensors for general measurement

Type CAS-04 CAS-05 CAS-14 CAS-15S CAS-15K CAS-16 CAS-17 CAS-19 CAS-23
Use Application Measurement Water-cooled engines Ship / generator
High durability
Heat sink mounting
Measurement Measurement Measurement use /
Measurement use
The plug insertion is possible
Super extra-fine /
Combined with Adapters
Very small screw type /
Combined with Adapters
Measuring range(Mpa) 0~25
Sensitivity(pc/bar) -28 -22 -4.5 -22 -13.5 -27 -19 -10 -10
Linearity(%FSO) ≦±0.7 ≦±0.5 ≦±1.0 ≦±0.5 ≦±0.7
Natural Frequency(KHz) >140
Insulation resistance(Ω) ≧10¹³
Operating range(℃) ~350
Cable connection(mm) M7 M5×0.5 M3.5×0.35
Cooling Non-cooling
Cable Low noise cable for exclusive use